Doku's spirit has caused enough trouble, it's time to
take him down. To get to him will be a challenge, however. Exit the back of the
Pyramid and follow the path down. You'll see a cut-scene of the ghostly Doku
passing behind a gate. You need the key for this gate first, so head the
opposite way to a Save Point. There's a shop here as
well (stock up!). Be certain to fill your Explosive and APFSDS Arrows, which
you'll need for late in Chapter 15. To the right is a chest with a Great Spirit Elixir. Follow the path, slicing bats
along the way, until you reach a small room with a portal. Enter the portal to
go to the Fiend Realm.

The Fiend Realm, which you will be visiting again
shortly, is just a fancy-looking arena. The walls instantly form when you near,
so feel free to wall run often. This time around you have an easy task as you
must beat a few dozen Wolverine Fiends that come in groups of three. If you
can't beat these fools by now, well, you wouldn't have gotten this far. Once
they're toast, a chest appears. Kick it to grab the Griffon Key and return to the Save Point for one last
save before chasing down Doku.

Use the key on the Griffon Gate. As you step to the
first hall, you'll see a cut-scene showing the arrival of the most annoying
enemy in Ninja Gaiden -- The Phantom Piranha. These bastards have one attack,
they dart and stick into Ryu, draining his soul. When stuck, Ryu cannot move and
other Piranha will come to stick as well. Hit X rapidly or use Ninpo. Those the
Piranha will respawn for a while, there is a finite number for each section, so
stand your ground and use the Vigoorian Flail. Keep one long combo going and let
them run right into it. You can also use Inferno Ninpo to destroy many of them.
When they stop coming, take a left and grab the Life of
the Gods from the chest.

Exit the dead end and continue down the main hallway. At
the intersection, take a right and go up the steps. To the left is a Great Devil Elixir and to the right is a dead body
holding Gen's Diary. Oh Gen, the scandalous things
you wrote! Grab these items and head back down the steps and continue down the
hall.

Doku passes by, but you can't follow without the Lion's
Key. Continue forward. Though you can avoid this small battle ahead by running
along the ledge on the right, you should get it on with the battle. There are a
few Phantom Piranha, but there's also a Clam Fiend. He has a sweeping laser like
the Pterodactyl boss you battled earlier. Jump when it comes. Use Ninpo to
quickly take out the Clam Fiend, and then Flail the Piranha. Kick the chest for an
Essence Bath then wall run up to the higher ledge. Walk counter-clockwise to the
chest in the corner and kick it for the Lion Key.
Return to where you last saw Doku and enter through the door.

Take a left and follow the path to a dead end and a Scarab. Now head the other way. When you reach the main
opening (you'll have three ways to go) head up the steps first to find a Great
Spirit Elixir. Once that's in hand, drop back down the steps and go right into a
hall with some Phantom Piranha. You know how to ace these suckers. Stand you're
ground until they are all toast, and then make your way down the long hall. You'll
hit an intersection. Take a left and look to the left immediately to see a
raised area with a Scarab in the back. Move forward
down the path and take the next left for a Great Spirit
Elixir. Finally, head take the last left and waste the Phantom Piranha.
Loads of fish await, but stand your ground. When all are dead, grab the Lioness Key from the chest and return to the big
intersection.

Hop down the steps to face a few Phantom Piranha and a
Clam Fiend. Heal up and step through the Lioness Door, it's time to finish off
Doku for good.

Boss: Doku's GhostAh Doku,
once so powerful and now just a ghost of your former self. All kidding aside,
Doku has almost all of the same attacks as before. This time, however, he's a
bit tougher. The fight tends to veer away from the walls more often than not,
taking them out of play more so than in your first battle with Doku. The camera
is also a problem, so you'll need to keep centering it for the best view. But
what really makes Doku tough this time is that it's much more difficult to
distinguish his attacks, particularly the Killer Combo.

Use your patented jump slash (A, Y). Your fighting
tactics are the same as the first fight with Doku. He has the flame breath and
he'll still try and grab. His only new attack to watch out for is that he can
shoot forward his hand for a grab. If he does this, jump out of the way and then
charge in to combo while he's distracted. Patience will win out, as will
avoiding the attacks, as in the last Doku battle. There's little other advice to
give here as this really is just a repeat of a previous conflict.